气候变化领域集成服务门户(CCPortal): Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities

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DOI	10.1016/j.epsl.2021.116785
	Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities
	Gama I.; Fischer K.M.; Eilon Z.; Krueger H.E.; Dalton C.A.; Flesch L.M.
发表日期	2021
ISSN	0012821X
卷号	560
英文摘要	The present-day lithospheric structure of Alaska is the result of a unique tectonic history of subduction and terrane accretion that controls upper plate thickness and rheology. To provide new constraints on the structure of the crust and upper mantle beneath Alaska, we jointly inverted Sp receiver functions and Rayleigh wave phase velocities to calculate shear-wave velocity profiles. Robust Sp receiver functions were obtained using a broad range of frequencies (2–100 s), time-domain deconvolution, and K-means cluster analysis. Tests of the Bayesian joint inversion with synthetic data illustrate that Sp receiver functions enhance the resolution of the velocity gradients at the Moho and the lithosphere-asthenosphere boundary, while Rayleigh surface waves provide information about absolute velocities. Our results show that in central Alaska, above the shallow slab, the continental lithosphere is thinnest (∼60 km) and the asthenosphere has its lowest velocities. This zone coincides with the Denali Volcanic Gap. The continental lithosphere thickens to the north beneath the Brooks Range and the northern Arctic Alaska terrane, reaching values of 110 to 130 km, with high lithospheric velocities that are comparable to Archean cratons. This pattern is consistent with a northward decrease in upper plate modification by melt and volatiles derived from the slab, in addition to intrinsic mantle velocity and viscosity differences between inherited lithospheric terranes. Lithospheric and asthenospheric velocities are not significantly different inside and outside of the Denali Volcanic Gap, but at the boundaries of this region lithospheric thickness increases rapidly to the north and gradually to the south. In the south, the subducting Yakutat plate is thicker (∼100–120 km) than the subducting Pacific plate (∼80–90 km), likely due to its thicker crust. © 2021 Elsevier B.V.
关键词	Alaska Transportable Array Bayesian inversion lithosphere-asthenosphere boundary mantle imaging Sp receiver functions
英文关键词	Acoustic wave velocity; Cluster analysis; K-means clustering; Lithology; Phase velocity; Plates (structural components); Rayleigh waves; Shear waves; Statistical tests; Structural geology; Time domain analysis; Volcanoes; Absolute velocities; Continental lithosphere; Lithosphere-asthenosphere boundary; Lithospheric structure; Lithospheric thickness; Rayleigh surface waves; Rayleigh-wave phase velocity; Shear wave velocity structure; Shear flow; Bayesian analysis; data inversion; lithospheric structure; numerical model; Pacific plate; plate motion; plate tectonics; Rayleigh wave; S-wave; seismic velocity; velocity structure; Alaska; Denali Fault Zone; United States
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203094
作者单位	Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, United States; Department of Earth Sciences, University of California, Santa Barbara, CA 93106, United States; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, United States
推荐引用方式 GB/T 7714	Gama I.,Fischer K.M.,Eilon Z.,et al. Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities[J],2021,560.
APA	Gama I.,Fischer K.M.,Eilon Z.,Krueger H.E.,Dalton C.A.,&Flesch L.M..(2021).Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities.Earth and Planetary Science Letters,560.
MLA	Gama I.,et al."Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities".Earth and Planetary Science Letters 560(2021).